In the beneficiating of various coals for the purpose of removing undesirable waste materials, the waste materials and finely divided coal particles are usually separated from the desired coal by hydraulic processing. As a result, aqueous coal sludge slurries are produced which contain very finely divided suspended solid particles. The solid portions of such slurries are often increased by separation procedures or merely natural settling in ponds. Such solids, because of their finely divided physical state, are not usable as a landfill material in that they have poor load supportive properties.
It is an object of the present invention to convert the solids content of aqueous coal sludges to a sedentary mass suitable as landfill.
It is another object of the invention to produce sedentary masses of such solids, which masses are far less prone to the effects of leaching, thus resulting in a considerable reduction in the level of contamination of adjacent ground waters by undesirable soluble elements or compounds contained in the sedentary masses.